U.S. Pat. No. 4,699,158 describes a smoking article which can be adjusted by rotation to vary air dilution, by varying the degree of rotation between openings. However, this smoking article may provide a resistance to draw which is substantially reduced when ventilation is increased.
The resistance to draw of a smoking article is a measure of the pressure required to force smoke through the smoking article at a certain specified rate. A smoking article can be configured by the manufacturing process to have a resistance to draw within a pre-defined range. The resistance to draw through a variable ventilation smoking article generally drops with increased ventilation.